Peroxisomal membrane proteins contain common Pex19p-binding sites that are an integral part of their targeting signals.
Peroxisomal membrane proteins contain common Pex19p-binding sites that are an integral part of their targeting signals.
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DOI：
10.1091/mbc.e04-03-0188
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发表时间：
2004-07
影响因子：
3.3
通讯作者：
H. Rottensteiner;A. Kramer;S. Lorenzen;Katharina Stein;C. Landgraf;R. Volkmer‐Engert;R. Erdmann
中科院分区：
文献类型：
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作者：
H. Rottensteiner;A. Kramer;S. Lorenzen;Katharina Stein;C. Landgraf;R. Volkmer‐Engert;R. Erdmann
过氧化物酶体膜蛋白（PMPs）的靶向是一个多步骤的过程，不仅需要识别细胞质中的PMPs，而且需要将其插入过氧化物酶体膜。因此，PMPs（mPTS）的靶向信号相当复杂。PMP识别事件的候选蛋白是Pex19p，其与大多数PMP相互作用。然而，相应的Pex19p结合位点是不明确的，并且目前对这些位点是否包含在mPTS内存在争议。通过合成肽扫描和酵母双杂交分析，我们确定和表征Pex19 p的结合位点Pex11 p和Pex13 p，两个PMPs从酿酒酵母。这些位点原来是由一个最小长度为11个氨基酸的短螺旋基序组成的。利用所获得的数据，证明可以通过应用模式搜索和预测矩阵来预测和实验验证其他几种PMP中的Pex19p结合位点。过氧化物酶体靶向的Pex13 p片段在没有Pex19 p结合位点的情况下错误定位于内质网。通过添加Pex11p的异源结合位点，恢复了Pex13p片段的过氧化物酶体靶向。我们得出结论，Pex19p结合位点是定义明确的实体，代表了mPTS的重要组成部分。
Targeting of peroxisomal membrane proteins (PMPs) is a multistep process that requires not only recognition of PMPs in the cytosol but also their insertion into the peroxisomal membrane. As a consequence, targeting signals of PMPs (mPTS) are rather complex. A candidate protein for the PMP recognition event is Pex19p, which interacts with most PMPs. However, the respective Pex19p-binding sites are ill-defined and it is currently disputed whether these sites are contained within mPTS. By using synthetic peptide scans and yeast two-hybrid analyses, we determined and characterized Pex19p-binding sites in Pex11p and Pex13p, two PMPs from Saccharomyces cerevisiae. The sites turned out to be composed of a short helical motif with a minimal length of 11 amino acids. With the acquired data, it proved possible to predict and experimentally verify Pex19p-binding sites in several other PMPs by applying a pattern search and a prediction matrix. A peroxisomally targeted Pex13p fragment became mislocalized to the endoplasmic reticulum in the absence of its Pex19p-binding site. By adding the heterologous binding site of Pex11p, peroxisomal targeting of the Pex13p fragment was restored. We conclude that Pex19p-binding sites are well-defined entities that represent an essential part of the mPTS.